Dual-band omnidirectional antennas play an important role in various wireless communication systems, particularly point to multipoint cellular infrastructure networks. Certain prior art dual-band omnidirectional antennas are tall in length and constructed of two vertically stacked antennas in the same radome with each antenna being fed independently. Other prior art dual-band antennas are tall in length and composed of two individually stacked antenna arrays within the same radome, combined by a single feed. In the latter, two individual antenna feeds are attached to a combiner either in the center of the antenna or at the bottom of the antenna, creating losses. Further, the antenna pattern is distorted by the contributions of the second antenna or the combiner itself. Other prior art dual-band omnidirectional antennas are located aside each other, whether in the same radome or independent, but generally result in distorted radiation patterns. This is due to interference with each other and as a result there is an effect on both elevation and azimuth radiation patterns. In addition, some prior art dual-band antennas use a multitude of stacked printed circuit boards adjacent each other, with each having an independent function. The stacked printed circuit boards are generally combined by means of a di-plexer.
It is an object of the present invention to alleviate the losses and the distorted radiation patterns that are found in prior art dual-band omnidirectional antennas.